Varghese Tomy, Shi Hairong
Department of Medical Physics, The University of Wisconsin-Madison, Madison, WI-53706, USA.
Ultrason Imaging. 2004 Jan;26(1):18-28. doi: 10.1177/016173460402600102.
Radiofrequency or microwave ablations are interstitial focal ablative therapies that can be used in a percutaneous fashion for treating tumors in the liver, kidney, and prostate. These modalities provide in situ destruction of tumors. We present a method for in-vivo elastographic visualization of the ablated regions in the liver during and after thermal therapy. In-vivo elastographic imaging uses compressions of the liver due to movement of the diaphragm during the respiratory cycle. Elastography of the liver and other abdominal organs has not been attempted previously due to the difficulty in providing controlled compressions. Gating of the data acquisition to the respiratory waveform would provide access to data where the compression increments are similar in both magnitude and direction, thereby enabling reproducible imaging of the thermal lesion or tumor. Comparison of elastograms with gross-pathology of ablated tissue illustrates the correspondence between elastographic image features and pathology. Ultrasound is routinely used to guide the rf ablation procedure, so the same imaging system could be used for elastographic imaging. Since the technique utilizes physiological motion of the diaphragm due to respiration, it may also be employed in the visualization of cancerous tumors in the liver.
射频或微波消融是一种间质聚焦消融疗法，可经皮用于治疗肝脏、肾脏和前列腺的肿瘤。这些方法可对肿瘤进行原位破坏。我们提出了一种在热疗期间及之后对肝脏中消融区域进行体内弹性成像可视化的方法。体内弹性成像利用呼吸周期中膈肌运动对肝脏产生的压迫。由于难以提供可控的压迫，此前尚未尝试对肝脏及其他腹部器官进行弹性成像。将数据采集与呼吸波形进行门控，可获取压缩增量在大小和方向上相似的数据，从而实现对热损伤或肿瘤的可重复成像。弹性图与消融组织大体病理学的比较说明了弹性成像特征与病理学之间的对应关系。超声通常用于引导射频消融手术，因此同一成像系统可用于弹性成像。由于该技术利用了呼吸引起的膈肌生理运动，它也可用于肝脏癌性肿瘤的可视化。
